Biological and chemical weapons, infectious diseases, and environmental pathogens threaten both military and civilian personnel. Current technology lacks the capability to accurately detect the presence of trace amounts of, for example, chemical and biological warfare agents quickly and reliably. The present invention seeks to improve on the sensitivity, speed and/or the reliability of such prior art sensors.
Current technologies include those involving detection of analytes labeled with a fluorescent, photo-luminescent, radioactive or enzymatic marker. For example, the technique of radioimmunoassay may measure the competition between radioactively labeled analyte and unlabeled analyte for binding sites on an antibody in an antiserum. Several deficiencies in radioimmunoassay methodology have been identified. First of all, it is necessary to make a physical separation of the antibody-bound, radiolabeled analyte from the free radiolabeled analyte. Furthermore, the methodology is very time-intensive and requires substantial labor to employ.
Another broad category of currently used sensors includes those that employ optical waveguides. Waveguide sensors typically have disadvantages of high sensitivity to changes in the ambient conditions such as temperature, resulting in undesirable signal to noise ratios.
Other traditional sensors may be configured to monitor the changes in the irradiance of several diffraction orders to detect the occurrence of a biological binding event. However, irradiance measurements are not sensitive enough for many applications and are sensitive to noise, resulting in difficulty in relating and quantifying the changes in the detected diffraction irradiance signal to an input stimulus.
Some exemplary issues involved with detection architectures may include sensitivity issues (e.g., a low limit of detection) with a high probability of detection (i.e., low false negatives); a low probability of false positives; and a rapid response time or various combinations of these issues.
In summary, some exemplary problems with traditional sensors may include complexity of the system needed to evaluate for the presence of an analyte; the intensive training required to operate such complex systems; relatively time-consuming detection processes to identify the presence of an analyte; and resolution of the sensor, or the ability to detect very small amounts of analyte.